@Pythagorean,
I have mentioned before that metaphysics requires meta-cognition.
This is not actually mysterious. Meta-cognitive skills are recognised in the context of understanding how people learn. A person who understands their own learning style and develops a learning strategy is said to have meta-cognitive skills. So it is a concept that is widely used in education.
In the context of philosophy, the meaning is the same but the implications are different. Awareness of one's own cognitive capacity would amount to a meta-cognitive analysis. Descartes' Cogito is an obvious example of meta-cognitive analysis. In this analysis, Descartes is asking himself, what is the most fundamental basis of knowledge, the one apodictic fact that everything else can be built on. The Cogito is part of the answer to that question. And of course, this was the culmination, or Descartes interpretation of, the whole tradition of such questioning, going back to Plato and Aristotle.
Why is this distinction useful? Because when we are asking questions about the nature of knowledge, we are not necessarily questioning the reality of the external world in an obvious or gross manner. We are questioning the nature of our own awareness and asking ourselves how we know what we know. It is as much about questioning the nature of what we know, or think we know, as questioning the nature of objects of perception. I think it is fair to say that natural science will always start from the presumption that nature herself is real, or at least will not start by asking the question, is there a more fundamental level of reality than nature. Whereas philosophy will at least entertain the idea that there might be different levels or deeper causes or some aspect of being which is not fully disclosed by the examination of nature as such.
Now it seems to me that to insist that ordinary cognition, or our common-sense perception of the world, is the touchstone of reality, that against which everything else should be judged, really denies the possibility of any kind of meta-cognitive strategy before you even set out. So, as Pythagorean remarked above, this really amounts to an anti-philosophy. It might clothe itself in philosophical verbiage, but it doesn't really amount to a deep questioning of one's assumptions about the nature of reality. It more or less starts at the same place as natural science, and then demands justification for the asking of philosophical questions.
It is actually an irony that this is nowadays called skepticism, in my opinion.